Section 21B. The unauthorized willful inspection of information contained in or set forth in a return or document filed with the commissioner, or of information which can identify a particular taxpayer that is received by the commissioner for the purposes of tax administration from the Internal Revenue Service or other taxing authority or derived from any other source, by (1) an employee of the commonwealth or a city or town therein, including the commissioner or a deputy, assistant, clerk, or assessor; (2) an employee of another state; (3) a person under contract with the commonwealth or an officer, director, or employee thereof; or (4) a person obtaining unauthorized access to a return, document, or information while the return, document, or information, including a return, document, or information stored in computer systems or computer files, is in the custody of the commissioner or of any other person or entity described in clauses (1) to (3), inclusive, is prohibited.

A violation of this subsection shall be punished by a fine of not more than $1,000 per return, document, or taxpayer, as the court determines, with respect to which information was inspected, or by imprisonment for not more than 1 year, or both, and by disqualification from holding office in the commonwealth for a period, not exceeding 3 years, as the court determines.

The determination by the commissioner that an employee of the department of revenue, or the determination by another agency head that an employee of such other agency has, in contravention of this subsection, willfully inspected information where the inspection was unauthorized and not protected by the good faith provision of this subsection, shall be grounds for dismissal of the employee.

A violation, as determined by the commissioner, of this subsection by any officer, director or employee of any person under contract with the commonwealth shall be grounds for prohibiting the officer, director or employee from working on the contract. A violation, as determined by the commissioner, of this subsection by a person under contract with the commonwealth, or an officer, director, or employee thereof, shall also be cause for terminating a current contract between the commonwealth and for prohibiting the contractor from entering into a future contract with the commonwealth.